Internal combustion engine



July 18,1939. c, D. DAVIS INTERNAL COMBUSTION ENGINE in \V M W\\\\\\\\\\\\\\\\\\\\\\ w Original Filed Aug. 19, 1935 INVENTOR Patented July is, 1939 UNlTED STATES.

2,166,464 INTERNAL COMBUSTION ENGINE Clarence D. Davis, Chicago, Ill;

Application August 19,

1935, Serial 36,783

Renewed November 18, 1938 10 Claims. (01. 123-66) My invention relates to internal combustion engines, and more particularly to the compression ignition type, in which opposed pistons are used, its essential object being to provide improved 5 means of operating one of the opposed pistons for scavenging and charging the working chamber.-

Referring to the accompanying drawing, ,which' shows a transverse sectional viewof an engine embodying my invention, I is the engine casing,

l 2 the crankshaft, 3 the connecting-rod and 4 the power piston'operating in cylinder 5. A piston 5 is opposed ,to piston 4 in cylinder 5. Piston 6 is formed with a stem 1 on which is mounted a piston 8. Piston B operates in cylinder 9. Cyl

inders land 5 are separated by the abutment Ill through which passes the stem 1 of piston 6.

A port I! in cylinder'5 controlled by piston 4 passes air and burned gases, the'burned gases passing out through the exhaust conduit Hand air being drawn through ports l4.

Ports H and I2 insure uniform initial pressures in the compression chambers formed on either side of abutment l0, piston 8 traveling above port II and piston 6 traveling below the top of port l2. Other conventional means may be used for controlling the initial pressures in the compression chambers on either side of abutment I. A fuel injection device l5 injects fuel into the combustion chamber formed between the pistons 4 and 6. I

With the pistons 4 and 6 'near their top dead centers fuel is injected by the device l5 into the compressed air charge between pistons 4 and 6.

- Combustion pressure will drive the piston Lon its power stroke while the compressed charge above piston 6 will serve as a cushion. When the piston 4' uncovers the port l2 the pressure between pistons 4 and fi-will be rapidly reduced by the escape of burned gases through port 12 40 and exhaust conduit l3. With the reduction of pressure under piston 6 the compressed. charge below abutment l0 will drive piston 6 down to the proximity of the port l2. The downward stroke of piston 6 will scavenge the cylinder 5 of burned gases.- The engine speed will allow pistons 4 and G to complete their downward strokes at approximately the same time. The air charge in the compression chamber between abutment I0 and piston 8 will absorb the kinetic energy of piston 6 on the scavenging stroke and serve to return piston 6 to the upper end of cylinder 5.

The return stroke of piston. 6, following the scavenging stroke will draw a charge of air into cylinder 5 between pistons 4 and 6 through ports i2 and I4. The engine speed will allow piston 6 to travel to the upper end of cylinder 5 by the time of closing of port l2 by piston 4.

The continued upward stroke of piston 4 following closing of port I! will compress the charges between pistons 4 and 6 and between 5 piston B and abutment Ill. When the speed of the engine is below normal, as when starting or idling, fuel can be'injected every second revolution of the crankshaft.

1i; will be understood that the admission of the 10 charge and the exhaust of the burned gases may be through separate ports and that various means may be used for controlling the flow offluid to and from the power chamber.

Although I have described what I deem to be a 16 preferred form of my invention herein, it is to be understood that interpretation of'the invention should be made only in view of its generic spirit and that of the claims.

Having thus described my invention, what I 20 claim and desire to secure by Letters Patent is:

1. In an internal combustion engine, the combination of a cylinder, opposed pistons in said cylinder and means, comprising a pair of fluid compression chambers, said pistons for alternately performing scavengv ing and suction strokes.

'2. In an internal combustion engine of the compression ignition" type, a cylinder,'a power piston in said cylinder, an auxiliary'piston op- 3 posed to said power piston insaid cylinder, a pair of fluid compression chambers adapted to reciprocate said auxiliary piston for alternately scavenging and charging said cylinder and ports in said cylinder controlled by the power piston for admission of the charge and'escape of the burned gases.

3. In internal combustion engine the combinationbf a cylinder, a crankshaft, a main piston in said cylinder operatively connected to said crankshaft for performing compression and power strokes, a secondary piston in said cylinder opposed to said main piston for performing scavenging and suction strokes, means of absorbing, 5 in a fluid compression chamber, .energyof the charge between said pistons, means of applying the energy in said compression chamber for oper ating said secondary piston on a scavenging stroke, means of absorbing, in a second fluid com: 50 pression chamber, the kinetic energy ofsaid secondary piston on the scavenging stroke, means of applying the energy in the last mentioned compression chamber for operating said secondary piston on an induction stroke, and inlet 55 for reciprocating one of 25 4. In an internal combustion engine, the coma bination of a cylinder, opposed pistons therein means for reciprocating one of said pistons f0 alternately scavenging and charging said cyl inder, said means including a pair of fluid cornpression chambers and inlet and exhaust; ports in said cylinder controlled by the second said piston,

5. In an internal combustion engine, the combination of a cylinder, a power piston in said cyl inder, an auxiliary piston opposed to said power piston, a fluid compression chamber tor actuating the auxiliary piston to scavenge the gases between the power piston and the auxiliary piston, a second fluid compression chamber for actuating the auxiliary piston to draw a charge of air between the power piston and the auxiliary. piston, means for transferring energy between the two said compression chambers, and inlet and exhaust ports in said cylinder controlled by the power piston.

6.-In an internal combustion engine, the combination of a power cylinder, 2. pair of auxiliary compression chambers in axial alinement with said power cylinder, a power piston in said power cylinder, an auxiliary piston structure having three faces entering respectively said power cylinder and said pair of auxiliary compression chambers, said auxiliary compression chambers containing an elastic fluid for reciprocation of said auxiliary piston structure, and an exhaust port and an air-inlet port in said power cylinder arranged to be uncovered by said power piston near the end of the power stroke.

7. In an internal combustion engine, the combination of a power cylinder, a power piston in said power cylinder, an auxiliary piston opposed to said power piston, a pair of auxiliary compression chambers containing an elastic fluid, piston means in said auxiliary compressionchambers'adapted to reciprocate said auxiliary piston, and inlet and exhaust ports in said power cylinder controlled by said power piston.

8. In an opposed piston internal combustion engine, in combination, a pair of auxiliary com.- pression chambers containing an elastic fluid, piston means in said auxiliary compression chambers adapted to reciprocate one of the opposed pistons and air-inlet means controlled by the second opposed piston.

9. In an opposed piston engine, a combustion chamber, a pair of auxiliary compression chambers containing an elastic fluid, piston means in said auxiliary compression chambers arranged to reciprocate one of the opposed pistons and air inlet and exhaust means controlled by the second opposed piston.

10. In an opposed piston internal combustion engine, a pair of elastic fluid compression cham-' bers, piston means in said-chambers adapted to reciprocate one of, the opposed pistons and air inlet and exhaust means controlled by the second opposed piston.

' CLARENCE D. DAVIS. 

